Modern automotive vehicles provide a variety of torque transfer systems that direct drive torque to multiple wheels to propel a vehicle along a surface. Such vehicle systems can include so-called four-wheel drive (4WD) systems, and all-wheel drive (AWD) systems, in which drive torque can be simultaneously transferred to all four wheels. In such systems, the torque transfer system can be automatically, or manually switched between a two-wheel drive (2WD) mode, if available, a 4WD mode, and/or an AWD mode.
4WD and AWD systems provide significant vehicle performance and safety advantages. 4WD and AWD systems, however, can include some disadvantages, such as reduced efficiency as a result of increased drive line friction, which results in lower fuel efficiency. For example, in some 4WD and AWD systems, the non-driven wheels can back-drive torque transfer components including, but not limited to an associated differential and prop shaft.